diff --git a/ph_model.gemspec b/ph_model.gemspec
index 2a3fd49..14da02a 100644
--- a/ph_model.gemspec
+++ b/ph_model.gemspec
@@ -18,11 +18,11 @@ Gem::Specification.new do |gem|
   gem.executables = gem.files.grep(%r{^bin/}).map { |f| File.basename(f) }
   gem.require_paths = ['lib']
 
-  gem.add_runtime_dependency 'activesupport', '> 3.2'
-  gem.add_runtime_dependency 'activemodel', '> 3.2'
+  gem.add_runtime_dependency 'activesupport', '> 5.0'
+  gem.add_runtime_dependency 'activemodel', '> 5.0'
 
   gem.add_development_dependency 'faraday'
-  gem.add_development_dependency 'bundler', '~> 2.3'
+  gem.add_development_dependency 'bundler', '> 2.2'
   gem.add_development_dependency 'rake', '> 10.0'
   gem.add_development_dependency 'rspec', '~> 3.0'
   gem.add_development_dependency 'rubygems-tasks', '~> 0.2'
@@ -30,6 +30,6 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency 'github_changelog_generator', '~> 1.6'
 
   # static analysis gems
-  gem.add_development_dependency 'rubocop', '~> 0.36.0'
+  gem.add_development_dependency 'rubocop', '~> 1.0'
   gem.add_development_dependency 'reek', '~> 3.10'
 end